Acoustic echo cancellation (AEC) is used in telecommunications devices to improve audio quality. In this environment, an echo is a delayed reoccurrence of an original signal in a received or retransmitted signal. Audio echo is caused by an acoustic echo path between the microphone and loudspeaker of a telecommunications device or system.
AEC is particularly useful in audio conferencing, in which the near-end microphone may pick up and retransmit far-end sounds played by the near-end loudspeaker. AEC components use the loudspeaker signal as a reference to cancel the far-end sounds from the near-end microphone audio signal.